You can cross reference 500 part numbers in one paste. We do not hold a customer BOM and will not invent one, so we tested the limit on the only real multi-line list we own: our 1,125-line Hong Kong stock list as at 23 September 2026. Three pastes. 176 lines returned nothing. 67 of those were a space.
Venatech Limited, an authorised Walsin distributor in Hong Kong, runs a free cross-reference tool that takes up to 500 pasted part numbers or an Excel or CSV drop. Most posts about such a tool describe a hypothetical bill of materials. We refuse to, because we have not been handed one and a fabricated BOM would make every figure here worthless. Instead we pasted our own list against all 203 of Walsin Technology (Walsin)’s parametric export files, 359,136 distinct part numbers, and counted what failed. Every part number below is real.
How many part numbers can you paste into the cross-reference tool at once?
500, and that is more than any one BOM needs and far less than a catalogue holds. We counted both ends of that statement. Our own stock list of 1,125 part numbers fits in three pastes. Walsin’s full MLCC shelf is 23,601 distinct part numbers and needs 48. The chip resistor shelf is 234,401 and needs 469.
| List | Distinct part numbers | Pastes at 500 per paste | Match / mismatch against the 500 limit |
|---|---|---|---|
| Our Hong Kong stock list, as at 23 September 2026 | 1,125 | 3 | Match — a real list clears the limit easily |
Walsin MLCC export, 00_ALL_MLCC_parts_combined.xlsx |
23,601 | 48 | Mismatch — a catalogue is not a paste job, use the Excel drop |
| Walsin chip resistor export, 137 files | 234,401 | 469 | Mismatch — same |
| All 203 Walsin export files combined | 359,136 | 719 | Mismatch — same |
So the 500-line limit is not the thing that will stop you. What stops you is whether the strings in your list match the strings in the catalogue, and that is the measurement nobody publishes. We ran it on ourselves.
What happens when you paste a real 1,125-line list of part numbers?
176 of 1,125 lines return nothing on an exact string match — 15.6%. We took the Catalogue code (website key) column of our stock snapshot as at 23 September 2026, matched every entry character-for-character against the 359,136 distinct part numbers in all 203 Walsin export files, and counted the failures. We have not seen this counted anywhere, including by us.
| Stage of the match | Lines that fail | Share of 1,125 |
|---|---|---|
| Exact string match against all 203 export files | 176 | 15.6% |
| After deleting embedded spaces on both sides | 109 | 9.7% |
| Of those 109, also absent from our 360,078-line master part-number set | 101 | 9.0% |
Those three figures are the same problem at three resolutions, and conflating them is easy. The published figure we have used before is 109 — the lines with no row in any export once whitespace is normalised. The 101 is the subset that is absent from our master list as well. The 176 is new, and it is the number a buyer actually experiences, because a paste box does not normalise anything before it looks.
Why do 67 of those 176 lines come back as soon as you delete a space?
Because Walsin’s export pads a resistance field with a blank and our stock register does not. 67 of the 176 failures are recovered by deleting a single space, and all 67 are chip resistor or resistor array lines — 66 and 1. Not one of the 1,125 stock codes contains a space. 39,162 of the 359,136 distinct part numbers in Walsin’s exports do, across 39,576 chip resistor rows.
| Stock line | Order code column | Catalogue code column | What Walsin’s export holds | Match / mismatch |
|---|---|---|---|---|
| 0402 thick film, 100 Ω, ±5% | WR04X101JTL |
WR04X101JTL |
WR04X101 JTL |
Mismatch on the string, match on the part — one embedded space |
| 0402 jumper | WR04X000PTL |
WR04X000PTL |
WR04X000 PTL |
Mismatch on the string, match on the part |
| 1206 thin film, 1.00 Ω | MF12E1R00FTL |
MF12E1R00FTL |
MF12E1R00FTL |
Match — ±1% codes fill the field, so no pad |
| 0201 MLCC, 100 pF, 16 V | 0201B101K160CT |
0201B101K160 |
0201B101K160 |
Mismatch on the order code, match on the catalogue code |
| 0603 precision resistor | WF06Q7502FTL |
WF06Q7502FTL |
nothing | Mismatch — no matching row in any of the 203 export files |
| X1/Y2 safety capacitor | S252B471K502ZT |
S252B471K502ZT |
nothing | Mismatch — no matching row, and the ZT suffix is not in the export’s format |
The pattern is arithmetic, not random. Walsin’s resistance field is four characters wide; a ±1% code such as 1R00 fills it and a ±5% code such as 101 does not, so the fourth position is padded. The tolerance letter at position 10 tells you which case you are in. We laid that out in why Walsin part numbers do not paste into your BOM. What is new here is the consequence at list scale: 38% of the failures on a real 1,125-line paste are not missing parts at all.
Which column should you paste — the order code or the catalogue code?
The catalogue code, and it is not close. Our stock register carries two part-number columns, and they disagree on 865 of 1,125 lines. Every one of those 865 differences is the same thing: a trailing CT packaging suffix on the order code that the parametric export does not carry. We matched both columns against all 203 export files.
| Column pasted | Lines that match a row in the export | Lines that return nothing | Match / mismatch |
|---|---|---|---|
Catalogue code (website key) |
949 of 1,125 | 176 | Match — this is the column to paste |
Order code (PO) |
185 of 1,125 | 940 | Mismatch — the CT suffix is not in the export |
Paste the column your purchasing system uses and 940 of 1,125 lines return nothing, which looks exactly like a catalogue with 940 holes in it and is in fact a suffix. 873 entries in our master part-number set end in CT, so both forms are real and orderable; they are just not the same string. The suffix itself is explained in the Walsin CT suffix and orderable part numbers.
This is the single cheapest fix available to anyone pasting a list: check which column you exported before you blame the tool.
Which 109 lines are genuinely absent, and what kind of part are they?
Mostly capacitors. After whitespace normalisation, 109 of 1,125 lines have no row in any of the 203 export files. We grouped them by the product line our own register assigns, and the shape is lopsided: 102 of the 109 are capacitors of one kind or another, and only 5 are chip resistors.
| Product line on the stock register | Lines held | Absent from all 203 exports | Match / mismatch between our shelf and Walsin’s published catalogue |
|---|---|---|---|
| MLCC | 732 | 91 | Mismatch on 12.4% — the largest gap, and the largest shelf |
| MLCC (specialty) | 132 | 11 | Mismatch on 8.3% — high Q, microwave and similar |
| Chip resistor | 254 | 5 | Match on 98% — once whitespace is handled |
| Safety capacitor | 3 | 1 | Mismatch on 1 of 3 |
| Other | 1 | 1 | Mismatch — 08052R152K501BA, a 15-character code in no export |
| Inductor · Resistor array | 3 | 0 | Match |
WR12X0000FTL and WF06U5363BTL are two of the five chip resistor codes with no matching row anywhere. S252B471K502ZT is the safety capacitor one. We hold these parts; Walsin’s published export does not describe them. That is a statement about the export, not about the parts, and it is why we tell you to ask rather than assume — see when a Walsin part number is not found.
Does the 500-line input limit bound what comes back out?
No, and the ratio is not small. The limit is on what you paste. What comes back is a candidate list, and a single specification routinely carries several part numbers. We counted, using case size, dielectric, capacitance, voltage and tolerance for capacitors and case size, resistance, tolerance, TCR and rated power for resistors.
| Shelf | Distinct specification signatures | Signatures holding more than one part number | Most part numbers on one signature |
|---|---|---|---|
| MLCC, 23,601 part numbers | 16,404 | 4,579 (27.9%) | 8 |
| Chip resistor, 234,401 part numbers | 88,341 | 50,598 (57.3%) | 15 |
More than half of all chip resistor specifications in Walsin’s catalogue carry two or more part numbers. So a 500-line paste is not a request for 500 answers; it is a request for 500 shortlists. That is a feature, because the differences between candidates are the information you need, and it is also why you should set the grade filter and the special-requirement filters before you read the output rather than after.
What should you do before you paste a 500-line BOM?
Three checks, two minutes. On our own 1,125 lines they move the failure count from 940 to 109, and not one of those recoveries involves a different part — only a different string. They are the difference between a clean pass and a list that looks half-empty for reasons that have nothing to do with availability.
- Paste the catalogue code column, not the purchase-order column. On our own list that is the difference between 176 failures and 940.
- Strip spaces from the list before you paste it, and expect them in the results. 39,162 distinct Walsin part numbers carry one. Use the free cross-reference tool with the downloadable template if you would rather drop an Excel or CSV than paste text.
- Send us the lines that still return nothing. On our own shelf that was 109 of 1,125, and we can answer those by hand.
Then check what is physically in Hong Kong on ready stock — 1,125 part numbers as at 23 September 2026, a dated snapshot and not a live feed. The resistor line sits on the Walsin chip resistor page. Our line runs from Hong Kong, Shenzhen, Singapore and Jiangmen, with Chengdu in preparation, and nowhere else. Unit 207, 2/F, Sun Ling Plaza, 30 On Kui Street, Fanling, N.T., Hong Kong. (852) 2628 4777.
The short version
The paste limit is 500 and it is not your problem. String matching is. We pasted our own 1,125-line stock list as at 23 September 2026 against all 203 Walsin export files: 176 lines returned nothing, 67 of those were recovered by deleting one space Walsin’s own export inserts, and 109 are genuinely absent — 101 of which are also outside our 360,078-line master set. Paste the purchase-order column instead and 940 of 1,125 fail, on a CT suffix. And the limit binds only on the way in: 50,598 of 88,341 chip resistor specifications carry more than one part number. Qualification stays with you — our job is to make sure a blank result means “we do not have it” and never “your spreadsheet had a space in it”.
Send us the list that came back half empty and we will tell you which lines were a string problem, which were a suffix, and which are genuinely not in Walsin’s published catalogue. And a question back: the last time a cross tool returned nothing on a line, did you check the part, or did you check the column you exported?
Frequently asked questions
How many part numbers can I paste into the Venatech cross-reference tool?
Up to 500 in one paste, or drop an Excel or CSV file with the part number in the first column. A downloadable template is on the page. Our own 1,125-line Hong Kong stock list fits in three pastes; Walsin’s full chip resistor catalogue of 234,401 distinct part numbers would take 469, which is what the file drop is for.
Why does a Walsin part number return nothing when I paste it?
Three reasons, measured on our own 1,125-line list. 67 failures were an embedded space Walsin’s export puts in the part number. 940 failures appear if you paste the purchase-order column, because it carries a trailing CT packaging suffix the export does not. Only 109 lines were genuinely absent from all 203 export files.
Should I paste the order code or the catalogue code?
The catalogue code. On our stock register the two columns disagree on 865 of 1,125 lines, always by a trailing CT suffix. Matching the catalogue code column against Walsin’s exports resolves 949 of 1,125 lines; matching the order code column resolves 185. Both strings are real and orderable, but only one is in the parametric export.
How many Walsin part numbers contain a space?
39,162 of the 359,136 distinct part numbers across all 203 Walsin export files, appearing on 39,576 chip resistor rows. The space sits in a four-character resistance field that a plus or minus 5 percent code only half fills. None of the 1,125 codes on our stock register contains one, which is exactly why the two lists disagree.
Does a 500-part paste return 500 results?
No. It returns up to 500 candidate lists. We counted the catalogue: 4,579 of 16,404 distinct capacitor specifications and 50,598 of 88,341 distinct chip resistor specifications carry more than one Walsin part number, up to 8 and 15 respectively. Set the grade and special-requirement filters before reading the output.
What does Venatech do with the lines that still return nothing?
We answer them by hand. On our own shelf that was 109 of 1,125 lines, 91 of them MLCC. We hold those parts and Walsin’s published export does not describe them, which is a statement about the export file and not about the part. We hold no affected-part or lifecycle list for any manufacturer and we will not imply one.
Is the Hong Kong stock list live?
No. It is a dated snapshot of 1,125 part numbers as at 23 September 2026, and quantities move. Treat every figure drawn from it as of that date, ask us to confirm a specific line before you plan a build, and use the enquiry form rather than assuming a quantity is still there.